Chirality

Vocabulary

achiral molecule

molecule that has a plane of symmetry and isomers that can be interconverted by rotation or reflection

Cahn-Ingold-Prelog system

system of nomenclature used with the IUPAC system to identify enantiomeric structures by name alone

chiral molecule

molecule that does not have a plane of symmetry and whose isomers cannot be interconverted by rotation or reflection

chirality

configuration, or handedness, of an asymmetric chemical compound

chirality center

single tetrahedral atom with four different groups

constitutional isomer

one of two or more molecules that have the same molecular formula but different structural arrangements of atoms and bonds

diastereomer

stereoisomer that is not a mirror image of the original compound and is not superposable on itself

enantiomer

stereoisomer that has a mirror image that is not superimposable on itself

Fischer projection

projection that represents a molecule's three-dimensional structure

isomer

one of two or more molecules that have the same molecular formula but different arrangements of atoms and bonds

meso compound

molecule that is achiral even though it contains chirality centers

optically active compound

substance that can rotate the plane of polarized light that is passed through it

optically inactive compound

substance that is not able to rotate the plane of polarized light that is passed through it

plane of symmetry

imaginary plane that bisects a molecule so that the two halves of the molecule are mirror images of each other

polarimeter

instrument used to measure the effect of optically active compounds on plane-polarized light

racemic mixture

50/50 mixture of enantiomers

resolution

process for the separation of racemic compounds into their enantiomers.

stereochemistry

field of study that is concerned with the structures of molecules in three dimensions

stereoisomer

one of two or more molecules that have the same molecular formula and bond structure but different arrangements of the three-dimensional orientation of the atoms

superimpose

to place or lay over something

superpose

to lay something upon another so as to make all like parts coincide